I bought a FMF Q4 and and DJ kit today. Other then my Twin Air filter and the slip on I'm going to keep it stock. Any thing I should know or do for tuning my bike at sea level? I did a 350 mile ride two weeks ago from 4k-7.5k feet and the bike ran great besides needing to use the choke a few times. I don't want to go to rich for power at sea level then be annoyed up in the mountains.

 

I am at 500ft ASL. See my mods below. The dyno showed 14.5 - 14.8 AFR after I installed stage 2 as per the instructions with the #128 main jet. The bike ran great.
After a few weeks I installed the #132 main jet. The result was that the bike picked up about 1 horsepower with the AFR a little below 13. 1200 miles later now, it's still running fine..

 

Got my exhaust on and the carb jetted. So far it runs fine, fires up good and sounds smooth on decel. I'll see how it goes the next few days.

I matched my jetting to this chart to people in similar situations as me.

https://docs.google.com/spreadsheet/...owsperpage=250

I'm not sure if I expected more or what but I'm not sure what I spent my money on at the moment. The low end feels slightly better, freeway might be better then stock but around town grunt feels about the same. Perhaps I need to experience my mods for more then 10 miles of riding. Any thoughts?

 

ive had alot of bikes in the past, and alot have had aftermarket pipes/mufflers

ive never had that blow away feeling when using them
usually its just louder maybe making you think its faster

On a newer bike I have I have an aftermarket speedo, has timers built into it that come on once the wheel moves
pretty accurate tool to measure any gains or losses on mods
but its only for that bike

its pretty heavily modified, big bore, cam, alot of tranny work
for a year I ran a full yoshimura exhaust
did 2 timer runs 0-30 and 0-60 the speeds I drive it all the time
switched back to stock exhaust, 1 mph faster top speed, and basically the same speed times although it was tenths of a second faster im not that picky on the times
to me its the same as the aftermarket exhaust, just super quiet

sort of the same experience on other bikes ive had just no real way to measure any gains

For a while now ive been on the stock exhaust hype
keeps more of a low profile and even if I did get gains at $500+ its just not enough to justify the cost

 

I'm a mechanic and have been for a long time. I should have taken my own advice but I shouldn't get to down because I haven't tested it enough yet. I do feel a difference but it's negligible. With that being said I always tell my customers "your car makes 225 hp, it has 5 valves per cylinder, dual over head cams and variable valve timing along with a turbo charger. The EPA mandates strict emissions and customers demand performance...you really think an engineer over looked 15 hp and 2 percent better mpg because a lousy air filter or cold air set up"? I doubt it.

Anyways, I think there is more to be had. Maybe not performance in speed and numbers but drivability and trail grunt...I hope.

I know this sounds insane, especially since I'm running a Q4 but I love the tone but is there any way to tone it down a bit? I know they have a quiet insert but is that pre installed? FMF states the header lowers it 1.5 decibels... is that significant? I want the tone but less noise for stealth mode when I need to take an urban short cut.

 

call me naive, but on these newer bike I think the engineers or who ever make the engines and all that do a pretty good job with what they have to work with
making sure it can work in all parts of the world too
you may loose a little here and there but I think they got them designed pretty well
Im sure with emissions they may be lean a little but they still run good to me

im guessing at the minimum the new exhaust weighs less then stock?
so maybe a small weight savings

unless you have access to a dyno its just too hard to know whats really happening with new parts

 

You are 100% correct if you change te pipe power is neglible. However, when you do a rejet and airbox mod its as simple as more air in, more fuel in , more air out = more power

 

I guess I could always try my luck with that KDX300 snorkel or what ever guys run...?

I know air quality, turbulence, flow rate...etc matters but generally if there is no pressure drop then gaining more flow won't matter. I'm going to hook a vacuum gauge on the air box tomorrow and see if any vacuum builds in the air box while ripping it down the road.

 

Currently, the only mods I run on my bike is the KDX200 Snorkel and a Twinair filter.
If there was any change at all, it was minimal. There could be some increased throttle response but I think it was mostly wishful thinking. That being said, the KDX Snorkel is a good deal wider than the stock one and its a cheap upgrade.

I dont run a aftermarket pipe currently. I cannot justify the price (and the stock EFI pipe is not as ugly as the Carb pipe). I decided to go with a big bore kit first which I will have installed this weekend.

I will probably will be one of the only people running big bore with a stock exhaust. I am a bit worried that it will be chocked up. Id like a FMF Q4 Pipe + Header but with customs, tax and shipping it would be 890$. I think ill hold off until I can buy it used off a private seller.

Now I HAVE seen dynos that show that a pipe give you gains, but for the price I think its minimal. A big bore kit costs the same as a new pipe and header and with that you will see guaranteed and very noticable gains...it seems like a no brainer.

If nothing else, you save 5 kilos, which is also pretty cool. I might "unplug" my stock exhaust a bit so the air flows easier. Marcelino did this and claims that it helps. He seems like he knows his ****.

 

YEP!

To get any noticeable power you have to do all three, open air box (remove lid or KDX snorkel), jetting, and a pipe. They rely on each other.